Line marking apparatus, system and method

Abstract

A line marking apparatus, for use in a system that includes a source of a narrow beam of radiation which extends substantially horizontally along or parallel to a line to be marked, includes a wheeled chassis and a line marking head for dispensing line marking material. The marking head is supported on the chassis for lateral movement relative thereto, which movement is controlled by a controller that includes a detector which is movable with the marking head and is positioned and directed to detect such a beam of radiation, the marking head being movable together with the detector in response to a detected beam. Lateral movement of the marking head is thereby controlled such that the head and the detector substantially follow the line to be marked irrespective of whether the chassis deviates from the line direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. application Ser. No. 11 / 658,975 filed Feb. 10, 2008 in respect of International application No. PCT / GB05 / 003093 filed 5 Aug. 2005 and claiming priority from U.K. patent application No. 0417517.0 filed Aug. 6, 2004.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates to line marking apparatus, to a line marking system, and to a method of marking a line. The invention may be used, for example, for marking lines on sports fields and the like.[0004]2. Description of Related Art[0005]Line marking apparatus for sports fields is well known and generally comprises a line marking head and a reservoir of line marking material mounted on a chassis provided with wheels. The line marking apparatus may be pushed by a user or may be self-powered with a seat and steering means for a user riding on the apparatus.[0006]Although the user can steer the apparatus and guide th...

AI Technical Summary

Benefits of technology

The present invention provides a line marking apparatus that can accurately mark a line on a surface, even if the surface is uneven. The apparatus includes a chassis with wheels and a line marking head that can move laterally on the chassis. The line marking head is supported by a detector that moves with the head and detects a beam of electromagnetic radiation that extends along the line to be marked. The detector is positioned and directed to detect the beam and the apparatus moves the line marking head in response to the beam. This allows the line marking head to follow the beam and accurately mark the line, even if the chassis is not perfectly aligned with the line. The line marking apparatus is easy to use and can be controlled by a user or a computer. The invention also includes a method for marking a line using the line marking apparatus.

Problems solved by technology

Although the user can steer the apparatus and guide the line marking head along a generally straight line, it is not possible for the user, for example when marking the edge of a football pitch, to maintain a substantially straight line over any significant distance and small lateral deviations are inevitable.

One of the straightness problems associated with stringing-out results from the possibility that the string may move while the line is being marked.

Stringing-out can also give rise to spurious paint marks on the surface being marked out.

If the line is then moved to mark a further line, any contact of the wet paint on the string with the surface being marked will give rise to spurious paint marks on the surface being marked out.

Such a system is relatively complex in that it is necessary to adjust the position of the entire vehicle in order to adjust the position of the line marking head.

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